Ship or boat hull construction

ABSTRACT

A hull for ships or boats comprised of two elongated demi-hulls integrally joined together generally along the centerline of the hull whereby each of the demi-hulls has a keel disposed along the length thereof on either side of the centerline of the hull. The keels extend from a point adjacent the bow of the hull downwardly and outwardly along the length thereof to a point intermediate of the hull from where the keels extend upwardly and outwardly to a point adjacent the stern of the hull. The keels and the demihulls are in continual diverging orientation with respect to each other throughout substantially the length of the hull, providing the hull with a generally inverted V-shaped diverging configuration along the bottom thereof.

United States Patent Knerr [451 July 11, 1972 [54] SHIP OR BOAT HULL CONSTRUCTION Primary Examiner-Andrew H. Farrell Attorney-Birch, Swindler, McKie & Beckett ABSTRACT A hull for ships or boats comprised of two elongated demihulls integrally joined together generally along the centerline of the hull whereby each of the demi-hulls has a keel disposed along the length thereof on either side of the centerline of the hull. The keels extend from a point adjacent the bow of the hull downwardly and outwardly along the length thereof to a point intermediate of the hull from where the heels extend upwardly and outwardly to a point adjacent the stern of the hull. The heels and the derni-hulls are in continual diverging orientation with respect to each other throughout substantially the length of the hull, providing the hull with a generally inverted V-shaped diverging configuration along the bottom thereof.

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INVENTOR HUGH S. KNERR B 846 SW? PATENTEDJUL 1 1 1972 SHEET 2 BF 2 m M W w W 5 $4 m m a m m .3 N my #5: @2593 Si n 55. 33: 53

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ATTORNEYS SIIIP OR BOAT HULL CONSTRUCTION BACKGROUND OF THE INVENTION 1. Field of Invention This invention relates generally to ships or boats and more particularly to a hull for ships or boats comprised of two demi hulls joined together in diverging orientation throughout substantially the length of the hull from bow to stem.

2. DESCRIPTION OF THE PRIOR ART Ships or boats having a hull with a generally inverted V- shaped bottom configuration have heretofore been known in the prior art. Moreover, ships or boats of the catamaran type which are essentially comprised of two separate hulls in parallel relationship are also well known in the prior art. The previously known prior art ships or boats of the above types while generally possessing good stability nevertheless have certain disadvantages.

Prior art ships or boats having inverted V-shaped bottoms, for example, while generally being capable of greater speeds, sacrifice certain load carrying characteristics. Other prior art ships or boats of this type are constructed so as to prohibit the smooth passage of water in a natural flow down under the hull and outwardly at the stern in a pattern which conforms with the V-shaped wake naturally formed behind any moving hull. Still other such prior art ships or boats are of complicated construction and therefore expensive and difficult to build. Prior art catamaran type ships or boats, while possessing generally good stability characteristics, do not possess the necessary speed and/or load carrying characteristics required in many shipping or boating operations.

SUMMARY OF THE INVENTION Among the objects of the present invention is to avoid the disadvantages of prior art ships or boats having a generally inverted V-shaped bottom configuration and provide an improved ship or boat hull construction particularly adapted for good speeds, while still posseming good stability and load carrying characteristics. In this regard it is a particularly important object of this invention to provide a hull for ships or boats which is comprised of two demi-hulls, each of which lie in planes non-parallel with one another and non-parallel with the planes of the final integrated hull.

It is another important object of the invention to provide a hull for a ship or boat which provides a natural flow of water downwardly and outwardly under the forebody as well as up wardly and outwardly under the afterbody of the hull, thereby merging naturally and smoothly into the V-shaped wake normally created by the passage of a ship or boat through the water. A further object of the invention is to provide a hull for a ship or boat which is simple in construction and may be fabricated with a minimum amount of labor thereby promoting maximum economy in the overall cost.

According to the present invention there is provided a hull for ships or boats comprised of two elongated demi-hulls in' tegrally joined together along the centerline of the hull whereby the keels of each demi-hull diverge down-wardly and outwardly from the bow of the hull to a point intermediate of the hull from where the keels then extend upwardly and outwardly as they approach the stern thereof. The keels and the demi-hulls are in continual diverging orientation with respect to each other through substantially the length of the hull, thus providing the hull with a generally inverted V-shaped diverging configuration along the bottom thereof. Each of the demihulls lie in planes non-parallel with each other and non-parallel with the planes of the integrated hull. The geometrical configuration of the hull permits the shell of the hull to be formed of a flat single curvature. The transverse framing of the hull is straight and intersects each of the two demi-hull keels at a constant included angle of 90 degrees.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects and advantages of the invention will become apparent by reference to the detailed description of the invention and the accompanying drawings which follow wherein:

FIG. 1 is a bottom plan view of a ship or boat hull construction according to the principles of the present invention;

FIG. 2 is a side elevational view of a ship or boat hull of the present invention showing the designer's waterline of the hull;

FIG. 3 is a front elevational view ofa ship or boat hull of the present invention;

FIG. 4 is a back elevational view of the ship or boat hull of the present invention; and

FIG. 5 is a schematic view illustrating a demi-hull keel profile and the angle at which the planes of the demi-hull intersect the waterline and baseline of an integrated hull of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, there is shown a ship or boat hull, generally designated by the numeral 10, essentially comprised of two demi-hulls 11 and 12. The term demi-hull as used herein denotes a less than normal hull. The two demi-hulls II and 12 are integrally joined together generally along the centerline 13 of the final integrated hull, as best shown in FIG. 1. The two demi-hulls are joined together at the bow 14 of the boat and extend rearwardly to the stem 15 of the boat in continual diverging orientation to form a generally inverted V- shaped configuration on the bottom 30 of the hull I0.

Each of the demi-hulls 11 and 12 is provided with a keel 16 and 17 disposed along its length on either side of the centerline 13 of the hull 10. The keels are spaced from the centerline beginning from a point adjacent the bow and continuing throughout the length of the hull 10.

The forebody of the hull is provided with a stem member I8 which extends downwardly and rearwardly from a point adjacent the bow 14 to a point part way back of the forebody of the hull. As best shown in FIGS. 1 and 3, the stem 18 has a flat bottom surface which is narrow at its front portion, widens at its mid portion, and then narrows again at its back portion. The stern 15 of the hull 10 is provided with a transom member 20 for connecting the side panel members 21 and 22 of the hull. As shown in FIG. 1, the transom 20 is comprised of a rectangular upper panel member 23 and a triangular shaped lower panel member 24. It is to be noted that triangular member 24 of transom 20 extends horizontally and forwardly from the stem 15 until it meets the centerline 13 of the hull.

Mounted on the top of the side members or panels 21 and 22 are upper side panels 25 and 26. The tops of the upper side panels 25 and 26 constitute the deck edge 27. Referring to FIG. 2, it is to be noted that the top of the hull 10 is higher at the bow l4 and at the stem 15 than in the center, with the top of the bow being of higher elevation than the top of the stern.

As shown in FIGS. 1 and 3, the generally inverted V-shaped configuration of the bottom 30 of the hull I0 is comprised of panel members 31 and 32 which extend from the centerline of the hull 10 downwardly and outwardly to the keels 16 and 17. The panels 31 and 32 are of a flat configuration and each may be comprised of an individual panel. The sides 2] and 22 as well as the bottom panel members 31 and 32 are of a flat sin gle curvature throughout the length of the hull.

Support for the bottom and side panel members are provided by internal bracing and supporting members. As shown most clearly in FIG. 3, the sides 21 and 22 are supported by straight frame members 33 which extend from the top of the sides downwardly and inwardly to the keels 16 and 17 of each demi-hull II and 12. The bottom panel members 31 and 32 are supported by straight frame members 34 which extend downwardly and outwardly from the centerline of the hull to the keels 16 and 17 of the demi-hulls 11 and 12. Both the bottom and side frame members 33 and 34 intersect the keels 16 and 17 at a constant angle to form an included angle of therebetween.

In FIGS. 2, 3, and 4 of the drawings, the designer's waterline of the ship or boat hull of the present invention is designated by the letters WL.

The developed true contour of the underwater portion of each of the demi-hull keels 16 and 17 of the hull of the present invention may be derived from the following mathematical formula:

Y (K) (sin X) [cos/1X 0.5) a

rrZ W wherein Y the depth dimension in radians (573) X the length in radians (57.3") e the base ofthe naperian logarithims (2.7 18) 1r the ratio of the circumference to the diameter of a circle (3.142), and

K a conversion factor to convert X and Y from radians to linear units.

Table of Calculated Values For Y For Specified Values of X Ship X Sin Cosh e Y Starad- K el1r X X+0.5 (lintion ians ear) 0 1.0272 0.74863 0 1.1211 1.643 0 &0.l57 1.0272 0.7486] 0.156 1.061 1.411 0.|80 1 0.309 1.0272 0.74863 0.309 1.018 1.210 0.293 1% 0.471 1.0272 0.74836 -0.454 1,000 L030 -0.360 2 0.628 1.0272 0.74863 -0.886 1.008 0.879 0.401 3 0.943 1.0272 0.74863 0.809 1.100 0.640 0.4315 5 1.57 1.0272 0.7486] -1.000 1.630 0.343 0.429 7 -2.20 1.0272 0.74863 -0.809 2.828 0183 0.322 E k-2.58 1.0272 0.74863 -0.454 4.069 0.125 O.l79 10 3.14 1.0272 0.74863 0 7.056 0.071 0 Once the true contour of the underwater portion of each of the two demi-hulls is derived according to the above formula, the configuration of the overall hull may be easily determined accordingly.

In the hull of the present invention having the geometrical configuration described above, the longitudinal, transverse and vertical planes of one derni-hull 16 are non-parallel to the longitudinal, transverse and vertical planes of the other demihull 17. Moreover, the longitudinal, transverse and vertical planes of each of the demi-hulls are non-parallel to the longitudinal, transverse and vertical planes of the hull 10. The longitudinal, transverse and vertical planes constitute the three primary planes of a hull.

The lengthwise vertical plane of each of the demi-hulls l1 and 12 and of each of the demi-hull keels l6 and 17 is shown in FIGS. 1 and 4 by the dotted lines 40. The lengthwise vertical plane 40 of each of the demi-hulls, including the keels, is canted outwardly at the bottom of the hull 10 to form an included angle therebetween of 30 measured in a plane transverse to the longitudinal plane of the hull.

As shown in FIG. 1, the lengthwise vertical planes 40 of the demi-hulls intersect the waterline of the hull at an included angle of l3" minutes measured in a horizontal plane of the hull.

1n the schematic drawing of FIG. 5, the axis of intersection of the lengthwise vertical planes of the demi-hulls is indicated by the line 41. As shown in FIG. 5, the lengthwise vertical planes of each of the demi-hulls intersect each other in a line which is inclined at an angle of 25 from the waterline of the hull, with the 25-angle being measured in a vertical plane extending lengthwise of the hull.

As further shown in FIG. 5, the lengthwise vertical plane of each demi-hull is inclined at an angle of 2 30 minutes from the waterline of the hull, with the 2 30 minute angle being measured in a vertical plane.

A hull designed according to the principles of the present invention affords many significant advantages. The geometrical configuration of the hull wherein the two demi-hulls diverge downwardly and outwardly from the bow to a point intermediate of the hull from where they diverge upwardly and outwardly as the stern of the hull is approached, provides a natural flow of water downwardly and outwardly under the forebody of the hull and a natural continuing flow of water upwardly and outwardly under the afterbody of the hull. The water thereby flows under the hull and outwardly and upwardly from the afterbody of the hull in a pattern which conforms with the V-shaped wake naturally formed behind any moving hull. This naturally diverging flow of water thereby permits a minimum of energy to be expended in moving the hull through the water. Accordingly, the speed of the hull is enhanced. Moreover, the natural flow of water under and back of the hull provides a maximum of stability while still permitting excellent load carrying characteristics. The shape of the hull therefore reflects a reasonable propulsion requirement, reasonable hydrostatic indices, and promises excellent hydrodynamic characteristics.

It is further to be noted that a hull constructed according to the principles of the present invention may be effected with a minimum amount of labor in fabricating and assembly, thereby promoting maximum economy in the overall cost of the hull. The particular demi-hull and keel configuration of the present invention permits straight framing members to be used to support both the sides and the bottom of the hull as well as permitting the shell of the hull to be ola flat single curvature throughout. It is to be understood that the invention is not limited to the particular embodiment described and shown herein and that it includes any modifications or equivalents within the scope of the appended claims.

What is claimed is:

1. A hull for ships comprising two elongated demi-hulls integrally joined generally along the centerline of said hull, each of said demi-hulls having a keel disposed along the length thereof on either side of said centerline,

said keels extending from a point adjacent the bow of said hull downwardly and outwardly along the length thereof to a point intermediate of said hull from where said keels extend upwardly and outwardly to a point adjacent the stern of said hull, said keels and said demi-hulls being in continual diverging orientation with respect to each other throughout substantially the length of said hull,

the developed true contour of the portion of each of said keels below the waterline of said hull being determined according to the mathematical formula together wherein Y= the depth dimension in radians (57.3") below the waterline of said hull X= the length in radians (573) e the base of the naperian logarithims (2.71 8) the ratio of the circumference to the diameter of a circle (3.142)

K a conversion factor to convert X to Y from radians to linear units.

2. A hull for ships comprising a bottom and sides,

two elongated demi-hulls integrally joined together generally along the centerline of said hull to form a generally inverted V-shaped configuration along substantially the entire length of said bottom,

each of said demi-hulls having a keel disposed along the length thereof on either side of said centerline,

said keels extending from a point adjacent the bow of said hull downwardly and outwardly along the length thereof to a point intermediate of said hull from where said keels extend upwardly and outwardly to a point adjacent the stern of said hull, said keels and said demihulls being in continual diverging orientation with respect to each other throughout substantially the length of said hull.

3. A hull as defined in claim 2, wherein said bottom is comprised of a panel member on each side of the apex of said inverted V-shaped configuration, each of said bottom panel members being of flat single curvature.

4. A hull as defined in claim 2, wherein each of said sides is of flat, single curvature.

5. A hull as defined in claim 2, which includes a plurality of spaced bottom frame members disposed inside said hull on said bottom on each side of the apex of said inverted V-shaped configuration, and a plurality of side frame members equally spaced with said bottom frame members and extending down each of said sides to each of said keels whereby said bottom and said side frame members intersect said keels at a constant angle to form an included angle of 90 therebetween.

6. A hull as defined in claim 5, wherein each of said bottom and side frame members are straight.

7. A hull for ships comprising two elongated demi-hulls integrally joineil together generally along the centerline of said hull,

each of said demi hulls having a keel disposed along the length thereof on either side of said centerline,

said keels extending from a point adjacent the bow of said hull downwardly and outwardly along the length thereof to a point intermediate of said hull from where said keels extend upwardly and outwardly to a point adjacent the stern of said hull, said keels and said demi-hulls being in continual diverging orientation with respect to each other throughout substantially the length of said hull, the lengthwise vertical plane of each of said demi-hulls, in-

eluding each of said keels, being canted outwardly at the bottom of said hull to form an included angle therebetween of 30 measured in a plane transverse to the longitudinal plane of said hull.

8. A hull as defined in claim 7, wherein the lengthwise vertical planes of each of said demi-hulls intersect each other in a line which is inclined at an angle of 25 from the waterline of said hull, said 25 angle being measured in a vertical plane extending lengthwise of said hull.

9. A hull as defined in claim 7, wherein the lengthwise vertical planes of said demi-hulls intersect the waterline of said hull at an included angle of 13 [5 minutes measured in a horizontal plane of said hull.

I0. A hull as defined in claim 7, wherein the longitudinal axis of the lengthwise vertical plane of each of said demi-hulls is inclined at an angle of 2 30 minutes from the waterline of said hull, said 2 30 minutes angle being measured in a vertical plane.

ll. A hull as defined in claim 7, which includes bottom and side panel members, each of said bottom and side panel members being of flat single curvature. 

1. A hull for ships comprising two elongated demi-hulls integrally joined together generally along the centerline of said hull, each of said demi-hulls having a keel disposed along the length thereof on either side of said centerline, said keels extending from a point adjacent the bow of said hull downwardly and outwardly along the length thereof to a point intermediate of said hull from where said keels extend upwardly and outwardly to a point adjacent the stern of said hull, said keels and said demi-hulls being in continual diverging orientation with respect to each other throughout substantially the length of said hull, the developed true contour of the portion of each of said keels below the waterline of said hull being determined according to the mathematical formula wherein Y the depth dimension in radians (57.3*) below the waterline of said hull X the length in radians (57.3*) e the base of the naperian logarithims (2.718) the ratio of the circumference to the diameter of a circle (3.142) K a conversion factor to convert X to Y from radians to linear units.
 2. A hull for ships comprising a bottom and sides, two elongated demi-hulls integrally joined together generally along the centerline of said hull to form a generally inverted V-shaped configuration along substantially the entire length of said bottom, each of said demi-hulls having a keel disposed along the length thereof on either side of said centerline, said keels extending from a point adjacent the bow of said hull downwardly and outwardly along the length thereof to a point intermediate of said hull from where said keels extend upwardly and outwardly to a point adjacent the stern of said hull, said keels and said demi-hulls being in continual diverging orientation with respect to each other throughout substantially the length of said hull.
 3. A hull as defined in claim 2, wherein said bottom is comprised of a panel member on each side of the apex of said inverted V-shaped configuration, each of said bottom panel members being of flat single curvature.
 4. A hull as defined in claim 2, wherein each of said sides is of flat, single curvature.
 5. A hull as defined in claim 2, which includes a plurality of spaced bottom frame members disposed inside said hull on said bottom on each side of the apex of said inverted V-shaped configuration, and a plurality of side frame members equally spaced with said bottom frame members and extending down each of said sides to each of said keels whereby said bottom and said side frame members intersect said keels at a constant angle to form an included angle of 90* therebetween.
 6. A hull as defined in claim 5, wherein each of said bottom and side frame members are straight.
 7. A hull for ships comprising two elongated demi-hulls integrally joined together generally along the centerline of said hull, each of said demi-hulls having a keel disposed along the length thereof on either side of said centerline, said keels extending from a point adjacent the bow of said hull downwardly and outwardly along the length thereof to a point intermediate of said hull from where said keels extend upwardly and outwardly to a point adjacent the stern of said hull, said keels and said demi-hulls being in continual diverging orientation with respect to each other throughout substantially the length of said hull, the lengthwise vertical plane of each of said demi-hulls, including each of said keels, being canted outwardly at the bottom of said hull to form an included angle therebetween of 30* measured in a plane transverse to the longitudinal plane of said hull.
 8. A hull as defined in claim 7, wherein the lengthwise vertical planes of each of said demi-hulls intersect each other in a line which is inclined at an angle of 25* from the waterline of said hull, said 25* angle being measured in a vertical plane extending lengthwise of said hull.
 9. A hull as defined in claim 7, wherein the lengthwise vertical planes of said demi-hulls intersect the waterline of said hull at an included angle of 13* 15 minutes measured in a horizontal plane of said hull.
 10. A hull as defined in claim 7, wherein the longitudinal axis of the lengthwise vertical plane of each of Said demi-hulls is inclined at an angle of 2* 30 minutes from the waterline of said hull, said 2* 30 minutes angle being measured in a vertical plane.
 11. A hull as defined in claim 7, which includes bottom and side panel members, each of said bottom and side panel members being of flat single curvature. 